With the explosive growth of wired/wireless Internet, various types of Internet televisions (TVs) are expected to be used widely in the future. Although audio/video (A/V) signal delivery over the wired/wireless Internet may not be able to replace existing broadcasting for the present, future broadcasting services may evolve into a hybrid service type that integrates a broadcasting network with the Internet. Unlike in the past when a dedicated network was used for content delivery between studios or content delivery to a secondary distribution network, in recent times, content is delivered through an Internet protocol (IP) network to reduce cost incurred by the use of a separate dedicated network and to cut down high equipment cost caused by a specified interface.
Current digital broadcasting is expected to evolve into stereo three-dimensional (3D) video broadcasting, ultra-high definition (UHD) broadcasting, multi-view 3D video broadcasting, hologram broadcasting, etc., and there is a prospect that a current Moving Picture Experts Group 2 (MPEG2)-transport stream (TS) may become inefficient because in each forward step, a larger amount of transmission is required. For example, since UHD broadcasting may have a resolution that is four-times (4K-level) or 16-times than that of an existing high definition (HD) TV, a 6-MHz TV program may be difficult to transmit in one channel despite application of a high-efficiency compression scheme. Thus, the MPEG-2 TS having a fixed-length packet of 188 bytes is inefficient to support a high data rate. Moreover, in an environment where all other networks than a broadcasting network change into IP networks, the MPEG-2 TS is difficult to use by mutual conversion with the IP. Hence, at the near, not to say immediate, moment when UHD broadcasting is to be commercialized, a new AV delivery format may be required which is IP-friendly and more efficient than the MPEG-2 TS.
FIG. 1 illustrates an example of a protocol information configuration defined for each service component in a general IP broadcasting network service.
Referring to FIG. 1, in a broadcasting service provided by an existing IP broadcasting network 100, a protocol is clearly defined for each service and details thereof are described in an electronic service guide (ESG) or an electronic program guide (EPG). Taking a digital video broadcasting-handheld (DVB-H)-based technique as an example, AV streaming uses a real-time transport protocol (RTP) as indicated by 102 and a file data service uses a file delivery over unidirectional transport (FLUTE) as indicated by 104. That is, a protocol specific to each service is used.